Roger Federer lost in the semifinals of the Australian Open for the third straight year. This time it was to Andy Murray in five sets with a chance to face NovakDjokovic in the finals. The loss shows that Federer has fallen away from the younger members of tennis' Big Four.

At 31 years old, Federer is slowing down while Djokovic (25), Murray (25) and Nadal (26) are still able to maneuver quite well. While the rivalries in the Big Four have given tennis fans plenty to cheer about, it was just a matter of time before Federer's seniority caught up with him.

Federer hasn't fallen completely, as he showed in 2012 he can still be successful. His biggest win of the year was Wimbledon when he was able to hold off Murray 4-6, 7-5, 6-3, 6-4. In that match, he settled after a fast start from Murray and handled him the rest of the way.

It was different this time around as Federer was constantly having to answer to Murray. The younger player was in control for the majority of the match and simple wore down the older Federer. Federer admitted as much, saying (h/t Telegraph):

Obviously, I was down in the score basically from the start. Definitely it was more of a chase. I was able to level it a couple of times. It was a tough match. I had my chances. Obviously you're going to go through a five setter with some regrets.

But overall I think Andy was a bit better than I was tonight. I had to find my range a little bit early on and then adjust my game style as well, the way I was playing.

Federer will win more tournaments, but this type of semifinal loss should be expected more and more. He simply can't last playing at the level of the other three players. They are seemingly raising their level of play with each tournament, leaving Federer behind.

The other issue at play in the Big Four is the health of Nadal's knees. Depending on that, he may be joining Federer slightly outside the top club. That could leave Murray as the lone challenger to Djokovic, who is seemingly leaving everybody behind with his dominant play.

As he ages, Federer's chances of contending will become fewer and fewer. The decrease in his physical ability has already begun. At this moment, it's clear Federer is starting to fall away from the rest of tennis' best players.